////////////////////////////////////////////
//
// A C++ interface to gnuplot. 
//
// This is a direct translation from the C interface
// written by N. Devillard (which is available from
// http://ndevilla.free.fr/gnuplot/).
//
// As in the C interface this uses pipes and so wont
// run on a system that does'nt have POSIX pipe 
// support
//
// Rajarshi Guha
// <rajarshi@presidency.com>
//
// 07/03/03
//
////////////////////////////////////////////

#include "Gnuplot.hh"
#include <stdarg.h>
#ifdef WIN32
#  include <io.h>
#else
#  include <fcntl.h>  // X_OK
#  include <unistd.h> // access
#  define PATH_MAXNAMESZ       4096
#endif
#include <iostream>
#include <fstream>
#include <sstream>
#include <list>

#if defined(WIN32)
#  define pclose _pclose
#  define popen  _popen
#  define access _access
#  define ACCESS_OK 0
#  define PATH_SEP ";"
#  define MKTEMP_AND_CHECK_FAILED(name) (_mktemp(name) == NULL)
#else
#  define ACCESS_OK X_OK
#  define PATH_SEP ":"
#  define MKTEMP_AND_CHECK_FAILED(name) (mkstemp(name) == -1)
#endif

using namespace std;

/////////////////////////////
//
// A string tokenizer taken from
// http://www.sunsite.ualberta.ca/
//        Documentation/Gnu/libstdc++-2.90.8/html/21_strings/stringtok_std_h.txt
//
/////////////////////////////

template <typename Container>
void
stringtok (Container &container, string const &in,
		   const char * const delimiters = " \t\n")
{
	const string::size_type len = in.length();

	string::size_type i = 0;

	while ( i < len )
	{
		// eat leading whitespace
		i = in.find_first_not_of (delimiters, i);
		if (i == string::npos)
			return;   // nothing left but white space

		// find the end of the token
		string::size_type j = in.find_first_of (delimiters, i);

		// push token
		if (j == string::npos) 
		{
			container.push_back (in.substr(i));
			return;
		} else
			container.push_back (in.substr(i, j-i));

		// set up for next loop
		i = j + 1;
	}
}

// ----------------------------------------------------------------------------

#ifdef WIN32
std::string Gnuplot::gnuplot_executable_ = "pgnuplot.exe";
#else
std::string Gnuplot::gnuplot_executable_ = "gnuplot";
#endif

// ----------------------------------------------------------------------------

Gnuplot::Gnuplot(void)
{
	init();
	set_style("points");
}

// ----------------------------------------------------------------------------

Gnuplot::Gnuplot(const string &style)
{
	init();
	set_style(style);
}

// ----------------------------------------------------------------------------

Gnuplot::Gnuplot(const string &title,
				 const string &style,
				 const string &labelx,  const string &labely,
				 vector<double> x, vector<double> y)
{
	init();

	if (x.size() == 0 || y.size() == 0)
		throw GnuplotException("vectors too small");

	if (style == "")
		this->set_style("lines");
	else
		this->set_style(style);

	if (labelx == "")
		this->set_xlabel("X");
	else
		this->set_xlabel(labelx);
	if (labely == "")
		this->set_ylabel("Y");
	else
		this->set_ylabel(labely);

	this->plot_xy(x,y,title);

	cout << "Press enter to continue" << endl;
	while (getchar() != '\n'){}
}

// ----------------------------------------------------------------------------

Gnuplot::Gnuplot(const string &title,  const string &style,
				 const string &labelx, const string &labely,
				 vector<double> x)
{
	init();

	if (x.size() == 0)
		throw GnuplotException("vector too small");
	if (!this->gnucmd)
		throw GnuplotException("Could'nt open connection to gnuplot");

	if (style == "")
		this->set_style("lines");
	else
		this->set_style(style);

	if (labelx == "")
		this->set_xlabel("X");
	else
		this->set_xlabel(labelx);
	if (labely == "")
		this->set_ylabel("Y");
	else
		this->set_ylabel(labely);

	this->plot_x(x,title);

	cout << "Press enter to continue" << endl;
	while (getchar() != '\n'){}
}

// ----------------------------------------------------------------------------

Gnuplot::~Gnuplot()
{
	if ((this->to_delete).size() > 0)
	{
		for (size_t i = 0; i < this->to_delete.size(); i++)
			remove(this->to_delete[i].c_str());
	}

	if (pclose(this->gnucmd) == -1)
		cerr << "Problem closing communication to gnuplot" << endl;

	return;
}

// ----------------------------------------------------------------------------

bool Gnuplot::get_program_path(const string pname)
{
	list<string> ls;
	char *path;

	path = getenv("PATH");
	if (!path)
		return false;

	stringtok(ls, path, PATH_SEP);

	for (list<string>::const_iterator i = ls.begin(); i != ls.end(); ++i)
	{    
		string tmp = (*i) + "/" + pname;
		if ( access(tmp.c_str(), ACCESS_OK) == 0 )
			return true;
	}

	return false;
}

// ----------------------------------------------------------------------------

void Gnuplot::reset_plot(void)
{       
	if (this->to_delete.size() > 0)
	{
		for (size_t i = 0; i < this->to_delete.size(); i++)
			remove(this->to_delete[i].c_str());
	}
	this->nplots = 0;
	return;
}

// ----------------------------------------------------------------------------

void Gnuplot::set_style(const string &stylestr)
{
	if (stylestr != "lines" &&
		stylestr != "points" &&
		stylestr != "linespoints" &&
		stylestr != "impulses" &&
		stylestr != "dots" &&
		stylestr != "steps" &&
		stylestr != "errorbars" &&
		stylestr != "boxes" &&
		stylestr != "boxerrorbars")
		this->pstyle = string("points");
	else
		this->pstyle = stylestr;
}

// ----------------------------------------------------------------------------

void Gnuplot::cmd(const char *_cmd, ...)
{
	va_list ap;
	char local_cmd[GP_CMD_SIZE];

	va_start(ap, _cmd);
	vsprintf(local_cmd, _cmd, ap);
	va_end(ap);

	strcat(local_cmd,"\n");
	fputs(local_cmd,this->gnucmd);
	fflush(this->gnucmd);
	return;
}

// ----------------------------------------------------------------------------

void Gnuplot::set_ylabel(const string &label)
{
	ostringstream cmdstr;

	cmdstr << "set xlabel \"" << label << "\"";
	this->cmd(cmdstr.str().c_str());

	return;
}

// ----------------------------------------------------------------------------

void Gnuplot::set_xlabel(const string &label)
{
	ostringstream cmdstr;

	cmdstr << "set xlabel \"" << label << "\"";
	this->cmd(cmdstr.str().c_str());

	return;
}

// ----------------------------------------------------------------------------

// Plots a linear equation (where you supply the
// slope and intercept)
//
void Gnuplot::plot_slope(double a, double b, const string &title)
{
	ostringstream stitle;
	ostringstream cmdstr;

	if (title == "")
		stitle << "no title";
	else
		stitle << title;

	if (this->nplots > 0)
		cmdstr << "replot " << a << " * x + " << b << " title \"" << stitle.str() << "\" with " << pstyle;
	else
		cmdstr << "plot " << a << " * x + " << b << " title \"" << stitle.str() << "\" with " << pstyle;
	this->cmd(cmdstr.str().c_str());
	this->nplots++;
	return;
}

// ----------------------------------------------------------------------------

// Plot an equation which is supplied as a string
// 
void Gnuplot::plot_equation(const string &equation, const string &title)
{
	string titlestr, plotstr;
	ostringstream cmdstr;

	if (title == "")
		titlestr = "no title";
	else
		titlestr = title;

	if (this->nplots > 0)
		plotstr = "replot";
	else
		plotstr = "plot";

	cmdstr << plotstr << " " << equation << " " << "title \"" << titlestr << "\" with " << this->pstyle;
	this->cmd(cmdstr.str().c_str());
	this->nplots++;

	return;
}

// ----------------------------------------------------------------------------

void Gnuplot::plot_x(vector<double> d, const string &title)
{
	ofstream tmp;
	ostringstream cmdstr;
#ifdef WIN32
	char name[] = "gnuplotiXXXXXX";
#else
	char name[] = "/tmp/gnuplotiXXXXXX";
#endif

	if (this->to_delete.size() == GP_MAX_TMP_FILES - 1)
	{
		cerr << "Maximum number of temporary files reached (" << GP_MAX_TMP_FILES << "): cannot open more files" << endl;
		return;
	}

	//
	//open temporary files for output
#ifdef WIN32
	if ( _mktemp(name) == NULL)
#else
	if ( mkstemp(name) == -1 )
#endif
	{
		cerr << "Cannot create temporary file: exiting plot" << endl;
		return;
	}
	tmp.open(name);
	if (tmp.bad())
	{
		cerr << "Cannot create temorary file: exiting plot" << endl;
		return;
	}

	//
	// Save the temporary filename
	// 
	this->to_delete.push_back(name);

	//
	// write the data to file
	//
	for (size_t i = 0; i < d.size(); i++)
		tmp << d[i] << endl;
	tmp.flush();    
	tmp.close();

	//
	// command to be sent to gnuplot
	//
	cmdstr << ( (this->nplots > 0) ? "replot " : "plot ");

	if (title.empty())
		cmdstr << "\"" << name << "\" with " << this->pstyle;
	else
		cmdstr << "\"" << name << "\" title \"" << title << "\" with " 
		<< this->pstyle;

	//
	// Do the actual plot
	//
	this->cmd(cmdstr.str().c_str());
	this->nplots++;

	return;
}

// ----------------------------------------------------------------------------

void Gnuplot::plot_xy(vector<double> x, vector<double> y, const string &title)
{
	ofstream tmp;
	ostringstream cmdstr;
#ifdef WIN32
	char name[] = "gnuplotiXXXXXX";
#else
	char name[] = "/tmp/gnuplotiXXXXXX";
#endif

	// should raise an exception
	if (x.size() != y.size())
		return;

	if ((this->to_delete).size() == GP_MAX_TMP_FILES - 1)
	{
		std::stringstream s;
		s << "Maximum number of temporary files reached (" 
			<< GP_MAX_TMP_FILES << "): cannot open more files" << endl;
		throw GnuplotException( s.str() );
	}

	//open temporary files for output
	//
	if (MKTEMP_AND_CHECK_FAILED(name))
		throw GnuplotException("Cannot create temporary file: exiting plot");

	tmp.open(name);
	if (tmp.bad())
		throw GnuplotException("Cannot create temorary file: exiting plot");

	// Save the temporary filename
	// 
	this->to_delete.push_back(name);

	// Write the data to file
	//
	size_t N = std::min(x.size(), y.size());
	for (size_t i = 0; i < N; i++)
		tmp << x[i] << " " << y[i] << endl;
	tmp.flush();    
	tmp.close();

	//
	// command to be sent to gnuplot
	//
	if (this->nplots > 0)
		cmdstr << "replot ";
	else cmdstr << "plot ";
	if (title == "")
		cmdstr << "\"" << name << "\" with " << this->pstyle;
	else
		cmdstr << "\"" << name << "\" title \"" << title << "\" with " << this->pstyle;

	//
	// Do the actual plot
	//
	this->cmd(cmdstr.str().c_str());
	this->nplots++;

	return;
}

// ----------------------------------------------------------------------------

void Gnuplot::init()
{
	if (!this->get_program_path(gnuplot_executable_))
	{
		this->valid = false;
		throw GnuplotException("Can't find gnuplot in your PATH");
	}

	this->gnucmd = popen(gnuplot_executable_.c_str(),"w");
	if (!this->gnucmd)
	{
		this->valid = false;
		throw GnuplotException("Couldn't open connection to gnuplot");
	}
	this->nplots = 0;
	this->valid = true;
}

// ============================================================================
